When longtime NHL agent Peter Wallen first saw Timothy Liljegren play, he was scouting talent at a tournament during Christmas for 15 year olds in the south of Sweden.

There’s a rule in Sweden that prohibits agencies from signing players until January of the year they turn 16. Wallen was simply doing his homework on the best young talent the country’s top minor hockey teams had to offer for the upcoming signing season.

But it was Liljegren – a 14-year-old playing against kids a year older and ineligible to be signed for more than a calendar year – that caught his eye.

“(Liljegren) had the talent like I never saw before,” Wallen said over the phone from the airport on his way to Toronto for the Maple Leafs rookie tournament. “He was clearly the best player in the tournament.”

A little more than a year later, Wallen — who represents Jonas Brodin, Gabriel Landeskog, Victor Hedman, John Klingberg and others — recruited...